RichM Posted September 24, 2017 Report Share Posted September 24, 2017 Afternoon, Yesterday I noticed a loss of power on my boat. I had to use significantly more revs to get the boat to turn 90 degrees even though there were virtually no winds. It seemed to be engaging forward and reverse gears OK and the engine sounds/revs OK but there's an evident lack of power even when cruising along. Suspecting a fouled prop, I opened the weed hatch only to find the prop to be 100% free of any debris but after inspecting the blades, I noticed one is slightly bent with a 1/2 inch cut in it. Problem is I am not sure how long it has been like that and although it shouldn't be like that, I don't know if it may be a red herring in regards to the loss of power. Any thoughts? Cheers RichM Link to comment Share on other sites More sharing options...
Stilllearning Posted September 24, 2017 Report Share Posted September 24, 2017 What gearbox does the boat have? If mechanical is clutch slippage possible? 1 Link to comment Share on other sites More sharing options...
cuthound Posted September 24, 2017 Report Share Posted September 24, 2017 (edited) Bent props usually manifest themselves as a vibration. If you have a hydraulic gearbox, have you checked the oil level recently? They tend to slip when low on oil, which may explain your problem. Edited September 24, 2017 by cuthound Phat Phingers 1 Link to comment Share on other sites More sharing options...
RichM Posted September 24, 2017 Author Report Share Posted September 24, 2017 10 minutes ago, Stilllearning said: What gearbox does the boat have? If mechanical is clutch slippage possible? 9 minutes ago, cuthound said: Bent props usually manifest themselves as a vibration. If you have a hydraulic gearbox, have you checked the oil level recently? They tend to slip when low on oil, which may explain your problem. Thanks both. The gearbox is a PRM 150 and the oil was changed only last month. The boat has been out 2/3 times since the oil was changed. Link to comment Share on other sites More sharing options...
Stilllearning Posted September 24, 2017 Report Share Posted September 24, 2017 3 minutes ago, RichM said: Thanks both. The gearbox is a PRM 150 and the oil was changed only last month. The boat has been out 2/3 times since the oil was changed. OK! So my next thought is, when you checked the prop, did you check the rudder to see if there's anything on it? 1 Link to comment Share on other sites More sharing options...
Boat&Bikes Posted September 24, 2017 Report Share Posted September 24, 2017 Too early for leaves? Ian. 1 Link to comment Share on other sites More sharing options...
Stilllearning Posted September 24, 2017 Report Share Posted September 24, 2017 15 minutes ago, ianali said: Too early for leaves? Ian. Good point. In these sorts of situations, it is often useful to study the wake from the prop as an aid to diagnosis. 1 Link to comment Share on other sites More sharing options...
cuthound Posted September 24, 2017 Report Share Posted September 24, 2017 28 minutes ago, RichM said: Thanks both. The gearbox is a PRM 150 and the oil was changed only last month. The boat has been out 2/3 times since the oil was changed. The gearbox could have developed a leak though, since you last changed the oil. 1 Link to comment Share on other sites More sharing options...
bizzard Posted September 24, 2017 Report Share Posted September 24, 2017 13 minutes ago, cuthound said: The gearbox could have developed a leak though, since you last changed the oil. If you have a gearbox oil drain pump, check the tube fittings for leaks especially where it connects at the gearbox drain hole underneath. Also the 150 is prone to leaking oil from the oil pump securing bolts which have little copper washers under the heads. The pump is the round thing sticking out the back of the box next to the output propshaft shaft coupling. The bolts usually get a touch slack as the copper washers squash over time, try tightening them a touch. But of course check the level oil first. 1 Link to comment Share on other sites More sharing options...
Tony Brooks Posted September 24, 2017 Report Share Posted September 24, 2017 54 minutes ago, ianali said: Too early for leaves? Ian. No, got a blade full on the North Oxford yesterday . It just started. 1 Link to comment Share on other sites More sharing options...
Bee Posted September 24, 2017 Report Share Posted September 24, 2017 Just have a look at the shaft as you rev up, if it whizzes round then there can't be a lot wrong, if it doesn't then something is slipping, 1 Link to comment Share on other sites More sharing options...
RichM Posted September 24, 2017 Author Report Share Posted September 24, 2017 35 minutes ago, bizzard said: If you have a gearbox oil drain pump, check the tube fittings for leaks especially where it connects at the gearbox drain hole underneath. Also the 150 is prone to leaking oil from the oil pump securing bolts which have little copper washers under the heads. The pump is the round thing sticking out the back of the box next to the output propshaft shaft coupling. The bolts usually get a touch slack as the copper washers squash over time, try tightening them a touch. But of course check the level oil first. I just put my hand under the gearbox and on the starboard side, it feels wet. It is also a little wet underneath/murky but it has never been the driest of bilges. I imagine this is the likely suspect? 18 minutes ago, Bee said: Just have a look at the shaft as you rev up, if it whizzes round then there can't be a lot wrong, if it doesn't then something is slipping, It whizzes round absolutely fine in forward and reverse gear. Gave it some welly too. 1 hour ago, Stilllearning said: OK! So my next thought is, when you checked the prop, did you check the rudder to see if there's anything on it? Had another look, admittedly I did not give the rudder a thorough check initially but it's free of debris. Link to comment Share on other sites More sharing options...
bizzard Posted September 24, 2017 Report Share Posted September 24, 2017 The oil pump I mentioned is starboard side'ish. Check the oil level on the dipstick Rich. Link to comment Share on other sites More sharing options...
bizzard Posted September 24, 2017 Report Share Posted September 24, 2017 The gearbox input shaft oil seal can leak oil too, but pretty rare. If it is its a gearbox out job. Link to comment Share on other sites More sharing options...
ditchcrawler Posted September 24, 2017 Report Share Posted September 24, 2017 2 hours ago, ianali said: Too early for leaves? Ian. No its not, I have been picking them up all week Link to comment Share on other sites More sharing options...
mross Posted September 24, 2017 Report Share Posted September 24, 2017 Is the towpath higher than normal? Perhaps you are on the bottom? 1 Link to comment Share on other sites More sharing options...
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